Drivers for renewal and reform of contemporary nursing curricula: A blueprint for change

The creation of a curriculum blueprint appropriate to the development of a professional nurse who is practice-ready for the current and future context of health service delivery must take account of the extant context as well as an unpredictable and sometimes ambiguous future. The curriculum renewal process itself ought to challenge existing long held ideals, practices, and sacred cows within the health and higher education sectors. There is much to consider and importantly curriculum developers need to be mindful of reform within the health sector and health workforce education, as well as the concomitant vision and requirements of the nursing profession. Curriculum must develop more than discipline knowledge and skills: it must provide an infrastructure for generic abilities both social and intellectual in order to better prepare students for the registered nurse role. This paper discusses a number of forces that are essential to consider in curriculum development in undergraduate nursing education. © eContent Management Pty Ltd

Quantum efficiency measurement of single photon detectors using photon pairs generated in optical fibers

Using the correlated signal and idler photon pairs generated in a dispersion shifted fiber by a pulsed pump, we measure the quantum efficiency of a InGaAs/InP avalanche photodiode-based single photon detector. Since the collection efficiency of photon pairs is a key parameter to correctly deduce the quantum efficiency, we carefully characterize the collection efficiency by studying correlation dependence of photon pairs upon the spectra of pump, signal and idler photons. This study allows us to obtain quantum efficiency of the single photon detector by using photon pairs with various kinds of bandwidths.Comment: 21pages, 6figures, 4tables, accepted for publication in J. Opt. Soc. Am.

The first accurate parallax distance to a black hole

Using astrometric VLBI observations, we have determined the parallax of the black hole X-ray binary V404 Cyg to be 0.418 +/- 0.024 milliarcseconds, corresponding to a distance of 2.39 +/- 0.14 kpc, significantly lower than the previously accepted value. This model-independent estimate is the most accurate distance to a Galactic stellar-mass black hole measured to date. With this new distance, we confirm that the source was not super-Eddington during its 1989 outburst. The fitted distance and proper motion imply that the black hole in this system likely formed in a supernova, with the peculiar velocity being consistent with a recoil (Blaauw) kick. The size of the quiescent jets inferred to exist in this system is less than 1.4 AU at 22 GHz. Astrometric observations of a larger sample of such systems would provide useful insights into the formation and properties of accreting stellar-mass black holes.Comment: Accepted for publication in ApJ Letters. 6 pages, 2 figure

A Laser Driven Grating Linac

The fields induced over a grating exposed to plane parallel light are explored. It is shown that acceleration is possible if either the particles travel skew to the grating lines, or if the radiation is falling at a skew angle onto the grating. A general theory of diffraction in this skew case is given. In one particular case numerical solutions are worked out for some deep grating. It is found that accelerating fields larger even than the initial fields can be obtained, the limit being set by resistive losses on the grating surface. Simple calculations are made to see what accelerating fields might be obtained using CO/sub 2/ lasers. Accelerations of 2 or 20 GeV per meter seem possible depending on whether the grating is allowed to be destroyed or not. Power requirements, injection and focussing are briefly discussed and no obvious difficulties are seen. It is concluded, therefore, that the proposed mechanism should be considered as a good candidate for the next generation of particle accelerators

Cerebral blood flow predicts differential neurotransmitter activity

Application of metabolic magnetic resonance imaging measures such as cerebral blood flow in translational medicine is limited by the unknown link of observed alterations to specific neurophysiological processes. In particular, the sensitivity of cerebral blood flow to activity changes in specific neurotransmitter systems remains unclear. We address this question by probing cerebral blood flow in healthy volunteers using seven established drugs with known dopaminergic, serotonergic, glutamatergic and GABAergic mechanisms of action. We use a novel framework aimed at disentangling the observed effects to contribution from underlying neurotransmitter systems. We find for all evaluated compounds a reliable spatial link of respective cerebral blood flow changes with underlying neurotransmitter receptor densities corresponding to their primary mechanisms of action. The strength of these associations with receptor density is mediated by respective drug affinities. These findings suggest that cerebral blood flow is a sensitive brain-wide in-vivo assay of metabolic demands across a variety of neurotransmitter systems in humans

Effects of galaxy-halo alignment and adiabatic contraction on gravitational lens statistics

We study the strong gravitational lens statistics of triaxial cold dark matter (CDM) halos occupied by central early-type galaxies. We calculate the image separation distribution for double, cusp and quad configurations. The ratios of image multiplicities at large separations are consistent with the triaxial NFW model, and at small separations are consistent with the singular isothermal ellipsoid (SIE) model. At all separations, the total lensing probability is enhanced by adiabatic contraction. If no adiabatic contraction is assumed, naked cusp configurations become dominant at approximately 2.5'', which is inconsistent with the data. We also show that at small-to-moderate separations, the image multiplicities depend sensitively on the alignment of the shapes of the luminous and dark matter projected density profiles. In constrast to other properties that affect these ratios, the degree of alignment does not have a significant effect on the total lensing probability. These correlations may therefore be constrained by comparing the theoretical image separation distribution to a sufficiently large lens sample from future wide and deep sky surveys such as Pan-Starrs, LSST and JDEM. Understanding the correlations in the shapes of galaxies and their dark matter halo is important for future weak lensing surveys.Comment: 10 pages, 7 figure

Invariant Synthesis for Incomplete Verification Engines

We propose a framework for synthesizing inductive invariants for incomplete verification engines, which soundly reduce logical problems in undecidable theories to decidable theories. Our framework is based on the counter-example guided inductive synthesis principle (CEGIS) and allows verification engines to communicate non-provability information to guide invariant synthesis. We show precisely how the verification engine can compute such non-provability information and how to build effective learning algorithms when invariants are expressed as Boolean combinations of a fixed set of predicates. Moreover, we evaluate our framework in two verification settings, one in which verification engines need to handle quantified formulas and one in which verification engines have to reason about heap properties expressed in an expressive but undecidable separation logic. Our experiments show that our invariant synthesis framework based on non-provability information can both effectively synthesize inductive invariants and adequately strengthen contracts across a large suite of programs

Generation of Photon Pairs in Dispersion Shift Fibers through Spontaneous Four Wave Mixing: Influence of Self-phase Modulation

Correlated signal and idler photon pairs with small detuning in the telecom band can be generated through spontaneous four-wave mixing in dispersion shift fibers. However, photons originated from other nonlinear processes in optical fibers, such as Raman scattering and self-phase modulation, may contaminate the photon pairs. It has been proved that photons produced by Raman scattering are the background noise of photon pairs. Here we show that photons induced by self-phase modulation of pump pulses are another origin of background noise. After studying the dependence of self-phase modulation induced photons in signal and idler bands, we demonstrate that the quantum correlation of photon pairs can be degraded by the self-phase modulation effect. The investigations are useful for characterizing and optimizing an all fiber source of photon pairs.Comment: 20 pages, 6 figure

EPW: A program for calculating the electron-phonon coupling using maximally localized Wannier functions

EPW (Electron-Phonon coupling using Wannier functions) is a program written in FORTRAN90 for calculating the electron-phonon coupling in periodic systems using density-functional perturbation theory and maximally-localized Wannier functions. EPW can calculate electron-phonon interaction self-energies, electron-phonon spectral functions, and total as well as mode-resolved electron-phonon coupling strengths. The calculation of the electron-phonon coupling requires a very accurate sampling of electron-phonon scattering processes throughout the Brillouin zone, hence reliable calculations can be prohibitively time-consuming. EPW combines the Kohn-Sham electronic eigenstates and the vibrational eigenmodes provided by the Quantum-ESPRESSO package [1] with the maximally localized Wannier functions provided by the wannier90 package [2] in order to generate electron-phonon matrix elements on arbitrarily dense Brillouin zone grids using a generalized Fourier interpolation. This feature of EPW leads to fast and accurate calculations of the electron-phonon coupling, and enables the study of the electron-phonon coupling in large and complex systems.Comment: 6 figure

Stellar Disks in Aquarius Dark Matter Haloes

We investigate the gravitational interactions between live stellar disks and their dark matter halos, using LCDM haloes similar in mass to that of the Milky Way taken from the Aquarius Project. We introduce the stellar disks by first allowing the haloes to respond to the influence of a growing rigid disk potential from z = 1.3 to z = 1.0. The rigid potential is then replaced with star particles which evolve self-consistently with the dark matter particles until z = 0.0. Regardless of the initial orientation of the disk, the inner parts of the haloes contract and change from prolate to oblate as the disk grows to its full size. When the disk normal is initially aligned with the major axis of the halo at z=1.3, the length of the major axis contracts and becomes the minor axis by z=1.0. Six out of the eight disks in our main set of simulations form bars, and five of the six bars experience a buckling instability that results in a sudden jump in the vertical stellar velocity dispersion and an accompanying drop in the m=2 Fourier amplitude of the disk surface density. The bars are not destroyed by the buckling but continue to grow until the present day. Bars are largely absent when the disk mass is reduced by a factor of two or more; the relative disk-to-halo mass is therefore a primary factor in bar formation and evolution. A subset of the disks is warped at the outskirts and contains prominent non-coplanar material with a ring-like structure. Many disks reorient by large angles between z=1 and z=0, following a coherent reorientation of their inner haloes. Larger reorientations produce more strongly warped disks, suggesting a tight link between the two phenomena. The origins of bars and warps appear independent: some disks with strong bars show no disturbances at the outskirts, while the disks with the weakest bars show severe warps.Comment: 19 pages, 13 figures, accepted MNRAS; fixed compatibility problem in figures 8,